Movement at the costovertebral joints, through the long axes of the necks of the ribs, results in raising and lowering their sternal ends; pump-handle rib motion. The first to sixth ribs are the ones primarily involved in this movement.

Which ribs are bucket handle?

The false ribs are dominated by a bucket handle action.

Which muscle causes pump handle movement?

[12] Contraction of the external intercostals raises the lateral part of the ribs causing a bucket handle motion that increases the transverse diameter of the thorax. The vertebrosternal ribs also follow a pump handle motion, which raises sternum and increases the anterior-posterior dimensions of the thorax.